1. Field of the Invention
The present invention relates to a hydraulic press of the type containing a pressure cell with a diaphragm of flexible material and a pad, influenced by said diaphragm, which is also of a flexible material, said press pressing workpieces against a tool and giving them the desired shape. A press of this kind has normally a very large working surface and is used, for example, in the manufacture of sheet-metal parts in the aviation industry, for example ribs and beams of various kinds.
2. The Prior Art
The press according to the invention constitutes a further development of the press described more closely in the application of Claesson et al., to be filed of even date herewith, corresponding to Swedish patent application 73164568, KN4599U, which has a pressure cell containing a bag-like diaphragm clamped between two disc-shaped attachment members. These attachment members are shaped so as to form an annular groove which is adjusted to an annular bead surrounding the opening of the diaphargm. In the said patent application, a satisfactory seal is secured between the diaphragm and the attachment members by means of a sealing ring in a second groove formed by the diaphragm bead and the attachment members. This construction is a great step forward and provides a considerably more reliable sealing than earlier constructions and makes it possible to raise the working pressure.